I'm a new member here -- and hoping for ideas and advice. A group of us are hoping to get microscopes into the hands of moms/dads/mentors and their kids. The idea is sort of like the old one about reading every night to your kid being important to their development. In this case, maybe looking together through a microscope once a week will help engage curiosity and creativity in fields where there will be future jobs. Or just having the scope around, for use after a walk in the woods, a day at the beach, or when some bug bites the dust. We'll be trying similar things with 3D printing machines and perhaps others -- the idea being having a sort of techy pretext to engage kids own curiosity about the real world and competence in finding out things for themselves.
Two main questions -- one very general and one somewhat specific. The general one -- has anyone run a program like this and have ideas or advice to offer? At this point we're thinking of running weekend groups where adult-kid teams can try various microscopes (or bring their own) and see if this is for them. If it is, we'll try to help them get good affordable scopes or, in some cases, donate a scope. So far, five scopes have gone out -- two to Moms and their kids and three to Dads and their kids.
Second question is with respect to affordable phase contrast microscopy. Seems that our pond and slough life looks better that way than under bright field. But I've been disappointed in the image quality of the few setups tried so far. These include a full set of Lomo phase optics on a mechanically decent DIN Japanese scope, an older set of AO 160mm optics on an AO Series 4 refitted with a LED lamp, and a partial set of AO infinity optics (only have the 40x and 100x working) on an AO Series 10. The latter is the best, so far, but the images still lack the sharpness, flat fields, contrast, and wider views of many older and affordable brightfield (Leitz, Olympus) scopes. So any advice of who makes decent phase optics that might be available affordably through sources like Ebay??
Microscopes for kids
Re: Microscopes for kids
Have you considered darkfield?
If the issue is kids being able to pick out the protists, they show up very well in darkfield. All of your brightfield scopes should be easily fitted for Darkfield for 10x and 20x objectives using a simple home made mask.
The colors are more vibrant and contrasty too - remember you are competing against video games
If the issue is kids being able to pick out the protists, they show up very well in darkfield. All of your brightfield scopes should be easily fitted for Darkfield for 10x and 20x objectives using a simple home made mask.
The colors are more vibrant and contrasty too - remember you are competing against video games
Re: Microscopes for kids
Welcome to the forum.
All this phase optics that you have tried are very capable. There are better Leitz apo Pv phase optics, but they are very expensive.
It is more likely that your eyes just don't like the phase image. Mine don't.
Or you did not run phase properly. Sorry to say this, but phase is not easy for beginners. Your optics have to been aligned perfectly and sample slides have to be very thin and free of mineral particles and have mininal water gap.
Maybe try oblique illumination. Simply block half to 75% of the condenser bottom, you would have simple oblique brightfield that way.
All this phase optics that you have tried are very capable. There are better Leitz apo Pv phase optics, but they are very expensive.
It is more likely that your eyes just don't like the phase image. Mine don't.
Or you did not run phase properly. Sorry to say this, but phase is not easy for beginners. Your optics have to been aligned perfectly and sample slides have to be very thin and free of mineral particles and have mininal water gap.
Maybe try oblique illumination. Simply block half to 75% of the condenser bottom, you would have simple oblique brightfield that way.
Last edited by zzffnn on Tue Dec 06, 2016 10:08 pm, edited 1 time in total.
Re: Microscopes for kids
And just to be on the same page, these phase objectives are being used with a phase condenser?
For me, phase is not hard to set up. You do need phase objectives which match up to the phase condenser and then you need to make sure the phase ring in the objective lines up with the phase rings in the condenser. You can eyeball it to line them up but it can be seen easier through a Phase telescope.
For me, phase is not hard to set up. You do need phase objectives which match up to the phase condenser and then you need to make sure the phase ring in the objective lines up with the phase rings in the condenser. You can eyeball it to line them up but it can be seen easier through a Phase telescope.
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apochronaut
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Re: Microscopes for kids
The AO phase microscope is an extremely good phase instrument, for an older achromatic system. There were 24 possible phase objectives for that scope and a 20mm f.o.v. If you are having trouble with that microscope, it likely has some sort of fault, or is being operated improperly. I would begin with the led retrofit. Leds are the latest fad in illumination but it is hard to retrofit most microscopes to led because the the led output is not as high as one is led to believe and the distribution pattern of the beam is different than that of a filament lamp. They just don't work too well with the lens system built into the illuminators of most microscopes. To replace the 18 watt illuminator, inherent to the 4, you will need about an 8 watt led , unless the illuminator is moved understage then you might get away with 5 watts, maybe a little less. I assume you want a full phase system, including 100x.
An AO 10 also is an excellent phase microscope , and has the possibility of 9 objective choices.
You aren't going to get any improvement over those two, with any Leitz or Olympus that resides in the same category of instrument but you will probably pay more , because of the name. Cough up a pile of extra dough, and put any number of names on the instrument and you probably could do somewhat better but rising above the image quality level of an AO 10 with phase planachros, is only really possible by moving up to planfluorites or planapos. Most of the phase planachromat systems are pretty similar dark phase systems, with some variance in contrast levels, unless they are designated differently as bright or anoptral, or B-Minus( an AO exclusive).
An AO 10 also is an excellent phase microscope , and has the possibility of 9 objective choices.
You aren't going to get any improvement over those two, with any Leitz or Olympus that resides in the same category of instrument but you will probably pay more , because of the name. Cough up a pile of extra dough, and put any number of names on the instrument and you probably could do somewhat better but rising above the image quality level of an AO 10 with phase planachros, is only really possible by moving up to planfluorites or planapos. Most of the phase planachromat systems are pretty similar dark phase systems, with some variance in contrast levels, unless they are designated differently as bright or anoptral, or B-Minus( an AO exclusive).
Re: Microscopes for kids
Thanks very much for the replies.
To answer some questions -- the three phase scopes (AO Series 4, AO Infinty 10, Lomo-Japanese half-breed) we've been using so far are properly set up and aligned. We're getting decent, just not great, images. None of the phase objectives at hand are plan and only one (an old AO Series 4) has yet been retrofitted to LED.
The Lomo and early AO phase lenses (160mm) are about the same -- not as sharp as I hoped and (especially at 40x) lacking contrast. I should edit the contrast part -- the phase contrast is working, with the phase ring and annulus centered perfectly, but the overall image seems to use only the middle grays -- not much (excepting the odd inclusion) being light gray or towards black.
The AO Series 10 has been the best of the three -- it has a wider range from light to dark on the same specimens at 40x -- but this is with only early infinity achromat lenses. Somewhow I'm expecting to see more of a range from light to dark (just phase shifted) and hoping to find the margins of the image still somewhat focused. We don't yet have any AO infinity plan achromat phase lenses -- better eyepieces have helped a bit.
One nice thing about the Series 4 is that it was pretty easy to retrofit it with a high powered Cree LED, with the LED at same spot as the old tungsten filament. Not entirely even illumination, but a reasonable facsimile of Kohler and brighter than the old bulb is possible.
Would the later plan achromat phase lenses be a noticeable step forward? Even better the 45mm DIN Reichert and Leica plan achromats?? I'm guessing these might be the 34mm parfocal AO phase lenses repackaged??
As for darkfield -- we've been doing it somewhat successfully. As Rod and zzffnn suggest, it's a pretty interesting image. Need a bit more light (these are older scopes) in most of them for more vivid results; but I'm slowly adding LED replacements.
If anyone has an extra AO 20x phase annulus they'd like to sell, I'd be very much interested. Have the lens and the Zernicke type condenser, but the annulus is missing.
So far it's been pretty fun to see parents and their kids take to this. One of the questions, of course, will be if these leads to any enduring interest in science, discovery, etc.
To answer some questions -- the three phase scopes (AO Series 4, AO Infinty 10, Lomo-Japanese half-breed) we've been using so far are properly set up and aligned. We're getting decent, just not great, images. None of the phase objectives at hand are plan and only one (an old AO Series 4) has yet been retrofitted to LED.
The Lomo and early AO phase lenses (160mm) are about the same -- not as sharp as I hoped and (especially at 40x) lacking contrast. I should edit the contrast part -- the phase contrast is working, with the phase ring and annulus centered perfectly, but the overall image seems to use only the middle grays -- not much (excepting the odd inclusion) being light gray or towards black.
The AO Series 10 has been the best of the three -- it has a wider range from light to dark on the same specimens at 40x -- but this is with only early infinity achromat lenses. Somewhow I'm expecting to see more of a range from light to dark (just phase shifted) and hoping to find the margins of the image still somewhat focused. We don't yet have any AO infinity plan achromat phase lenses -- better eyepieces have helped a bit.
One nice thing about the Series 4 is that it was pretty easy to retrofit it with a high powered Cree LED, with the LED at same spot as the old tungsten filament. Not entirely even illumination, but a reasonable facsimile of Kohler and brighter than the old bulb is possible.
Would the later plan achromat phase lenses be a noticeable step forward? Even better the 45mm DIN Reichert and Leica plan achromats?? I'm guessing these might be the 34mm parfocal AO phase lenses repackaged??
As for darkfield -- we've been doing it somewhat successfully. As Rod and zzffnn suggest, it's a pretty interesting image. Need a bit more light (these are older scopes) in most of them for more vivid results; but I'm slowly adding LED replacements.
If anyone has an extra AO 20x phase annulus they'd like to sell, I'd be very much interested. Have the lens and the Zernicke type condenser, but the annulus is missing.
So far it's been pretty fun to see parents and their kids take to this. One of the questions, of course, will be if these leads to any enduring interest in science, discovery, etc.
Re: Microscopes for kids
I am working with public libraries to get microscopes into the hands of interested parties, adults and kids alike. I have been very fortunate to find several libraries that are willing to invest the time and effort necessary to have the microscope kits available for check-out.
We are using reasonably simple compound and stereo microscope and we have built kits so there is something to work with once the scope is checked out.
Our kits have a nylon carrying case with a storage drawer at the bottom (the scope sits on the top of the drawer cabinet). The scope fits in a receiver and is secured by the straps of the carrying case so that it does not bounce around when in transit. We have plastic slides and cover slips, a wide variety of prepared slides from which to choose, a couple of plastic petri dishes and pipettes, some lens tissue and the necessary instruction sheets. We also have a nice little cell phone mount that can be easily attached to the scope.
We offer a class about the microscopes which everyone must complete before they can check out the scopes.
My part in the project is to provide and maintain the kits and the library provides the books. So far it's working well.
lorez
We are using reasonably simple compound and stereo microscope and we have built kits so there is something to work with once the scope is checked out.
Our kits have a nylon carrying case with a storage drawer at the bottom (the scope sits on the top of the drawer cabinet). The scope fits in a receiver and is secured by the straps of the carrying case so that it does not bounce around when in transit. We have plastic slides and cover slips, a wide variety of prepared slides from which to choose, a couple of plastic petri dishes and pipettes, some lens tissue and the necessary instruction sheets. We also have a nice little cell phone mount that can be easily attached to the scope.
We offer a class about the microscopes which everyone must complete before they can check out the scopes.
My part in the project is to provide and maintain the kits and the library provides the books. So far it's working well.
lorez
Re: Microscopes for kids
Very cool, Lorez. We hadn't thought of the local library (which happens to have a good forward-thinking librarian) as a venue.
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apochronaut
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Re: Microscopes for kids
Have you investigated the heads to see if there is any film on the surfaces? Older microscopes, unless they have been cleaned fairly recently will almost always have a light deposit of fine airborne debris on prisms, mirrors and windows in the head. It can be quite bad, if the unit was in the hands of a smoker. Ditto for the components in the illumination path. This will cut down contrast dramatically. The infinity series objectives, will have a slightly contrastier image than the 160mm objectives. The 4 has a compensating lens in the yoke just above the nosepiece. This can get neglected for years and get pretty murky, seriously degrading the image, or if it is missing altogether.
The eyepieces for the two AO series are quite specific and not interchangeable. You can't just swap eyepieces around and expect to maintain the optical corrections, built into the system. The 4 uses # 146 10x w.f., with a 20mm f.o.v. Changing to other eyepieces, might just accidentally be o.k. but your comment about lack of planarity sounds suspicious. The series 4 achromats, had a typical level of field curvarture for their era. One of the things the compensating lens does is flatten the field somewhat, as well as correct for lateral chromatic aberration. so the resultant image is close to plan, or about what we would call semi-plan or neoplan these days. Most other eyepieces, would likely be a mis-match with the degree of compensation in the system. Recently, I tried a pair of Olympus WK 10x 20L in a 4, on someones reommendation. They look really impressive, on the microscope. The central image is almost as good as the # 146 but the contrast surprisingly was poorer and there is a whif of chromatic aberration at the edge of the 20mm field....definitely not an improvement.
The series 10 uses, cat.# 176 10x w.f. eyepieces. They have a 19mm f.o.v. Later developed # 180 will usually work too, as long as all is aligned perfectly, otherwise there is a diffraction ghost near one edge. Again these are well matched to the system and hard to replace with much better.
The planachromat, dark phase objectives became better in increments, as the objective series they were based on improved. They went through 4 different planachro 100x 1.25 lenses over about 20 years, # 1024,1029,1129 and 1309, with each successive one attaining an improved level of performance in one or several ways. I would definitely say, that the later the production the better. They did not change the cat. # of the phase lenses , when they morphed to a newer objective design, so you have to know the design features, in order to tell when they were made.
The Reichert D.I.N. objectives are not just repackaged 34mm objectives, although some are based on them. Others are based on the Reichert Austria , D.I.N. objectives, which emerged in the early 70's. Some of the Neoplans( semi-plan) lenses are Reichert based( the 10, for sure) and some AO based. This is true for the planachros too but most seem to be AO derivatives. The D.I.N. objectives have superior optical characteristics, to the 34mm ones generally but in order to retrofit them to an older stand, you must use a 400 series head, because the telon lens corrections are slightly different.
It doesn't sound positive that the led illuminated field on the 4 is not even. One of the basics of good phase contrast, is the evenness of the field, thus the necessity for kohler.
The eyepieces for the two AO series are quite specific and not interchangeable. You can't just swap eyepieces around and expect to maintain the optical corrections, built into the system. The 4 uses # 146 10x w.f., with a 20mm f.o.v. Changing to other eyepieces, might just accidentally be o.k. but your comment about lack of planarity sounds suspicious. The series 4 achromats, had a typical level of field curvarture for their era. One of the things the compensating lens does is flatten the field somewhat, as well as correct for lateral chromatic aberration. so the resultant image is close to plan, or about what we would call semi-plan or neoplan these days. Most other eyepieces, would likely be a mis-match with the degree of compensation in the system. Recently, I tried a pair of Olympus WK 10x 20L in a 4, on someones reommendation. They look really impressive, on the microscope. The central image is almost as good as the # 146 but the contrast surprisingly was poorer and there is a whif of chromatic aberration at the edge of the 20mm field....definitely not an improvement.
The series 10 uses, cat.# 176 10x w.f. eyepieces. They have a 19mm f.o.v. Later developed # 180 will usually work too, as long as all is aligned perfectly, otherwise there is a diffraction ghost near one edge. Again these are well matched to the system and hard to replace with much better.
The planachromat, dark phase objectives became better in increments, as the objective series they were based on improved. They went through 4 different planachro 100x 1.25 lenses over about 20 years, # 1024,1029,1129 and 1309, with each successive one attaining an improved level of performance in one or several ways. I would definitely say, that the later the production the better. They did not change the cat. # of the phase lenses , when they morphed to a newer objective design, so you have to know the design features, in order to tell when they were made.
The Reichert D.I.N. objectives are not just repackaged 34mm objectives, although some are based on them. Others are based on the Reichert Austria , D.I.N. objectives, which emerged in the early 70's. Some of the Neoplans( semi-plan) lenses are Reichert based( the 10, for sure) and some AO based. This is true for the planachros too but most seem to be AO derivatives. The D.I.N. objectives have superior optical characteristics, to the 34mm ones generally but in order to retrofit them to an older stand, you must use a 400 series head, because the telon lens corrections are slightly different.
It doesn't sound positive that the led illuminated field on the 4 is not even. One of the basics of good phase contrast, is the evenness of the field, thus the necessity for kohler.
Re: Microscopes for kids
Apochronaut -- thanks very much for that informative reply. Looks like I have some more work to do. I didn't clean the interior glass on the AO 4 and the oculars may well have been mismatched. Do think I have a pair of the proper 146 oculars around.
The LED retrofit is a bit better than the original low wattage tungsten lamp, but probably wouldn't hurt to fiddle around with it a bit for a more even field.
If anyone knows a source of AO plan phase objectives, please let me know. I've posted a "want to buy" on what I hope is the appropriate sub forum.
The LED retrofit is a bit better than the original low wattage tungsten lamp, but probably wouldn't hurt to fiddle around with it a bit for a more even field.
If anyone knows a source of AO plan phase objectives, please let me know. I've posted a "want to buy" on what I hope is the appropriate sub forum.
Re: Microscopes for kids
Just to follow up -- the AO 4 had #176 oculars on it. Swapping them for a pair of #146 made a definite improvement. Thanks, again, Apochronaut.
With respect to the compensating lens in the Series 4 -- I'm not sure if there is one missing or not. This scope has a trinocular head with what looks to be a flat or near flat coated lens that slides into play. It also has threads (but nothing threaded in) in the stand just above the rotating objective holder. Are we missing a compensating lens there?
With respect to the compensating lens in the Series 4 -- I'm not sure if there is one missing or not. This scope has a trinocular head with what looks to be a flat or near flat coated lens that slides into play. It also has threads (but nothing threaded in) in the stand just above the rotating objective holder. Are we missing a compensating lens there?
Re: Microscopes for kids
PeteM wrote:Just to follow up -- the AO 4 had #176 oculars on it. Swapping them for a pair of #146 made a definite improvement. Thanks, again, Apochronaut.
>> #176 EP is matched for infinity tube lens in AO10/110. I tried it on 160 tube length scopes before and it does looked off.
With respect to the compensating lens in the Series 4 -- I'm not sure if there is one missing or not. This scope has a trinocular head with what looks to be a flat or near flat coated lens that slides into play.
>> That is probably beam splitter for camera tube.
It also has threads (but nothing threaded in) in the stand just above the rotating objective holder. Are we missing a compensating lens there?
>> It sounds like you are missing compens lens. Maybe take a photo, with head removed, and looking into the inside of stand above objective turret?
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apochronaut
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Re: Microscopes for kids
Yes, you are missing the compensating lens if there are just threads visible. Putting one of those in place, will go a long way towards getting that nice microscope to where it should be. If yours has a little knurled lockscrew in the yoke that locks the nosepiece in place, you have the quick change nosepiece version. There were 7 distinct phase systems, some in complete sets of 4 and a couple in sets of 2, plus standard achromats and apochromats for it, so with that nosepiece, an easy transfer to another system is pretty fast. I have an extra compensating lens for you.
I might have some spare planachro dark phase. I will scout around and see if there are any with a few people who might have that sort of thing.
I might have some spare planachro dark phase. I will scout around and see if there are any with a few people who might have that sort of thing.
Re: Microscopes for kids
Apochronaut -- thanks very much. I'm happy to pay what you think would be fair for the parts. Hoping not to go broke on these projects; but I'm willing to consider them contributions to the next generation.
As for what I have in this Series 4 scope -- the trinocular head slider has glass cover plates viewable from below in both the regular viewing (a slightly blue tinted coating, possibly a VERY low power lens) and what looks to be just a clear protective cover when the prism is shuttled over to the photo tube.
The stand itself doesn't look to have a quick change nosepiece. Just two concentrically threaded sections. At the top, slighly smaller in diameter with about a 1/8" threaded section; possibly where the correction lens goes. I can snap a photo if that helps.
Again -- thank you.
As for what I have in this Series 4 scope -- the trinocular head slider has glass cover plates viewable from below in both the regular viewing (a slightly blue tinted coating, possibly a VERY low power lens) and what looks to be just a clear protective cover when the prism is shuttled over to the photo tube.
The stand itself doesn't look to have a quick change nosepiece. Just two concentrically threaded sections. At the top, slighly smaller in diameter with about a 1/8" threaded section; possibly where the correction lens goes. I can snap a photo if that helps.
Again -- thank you.
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apochronaut
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Re: Microscopes for kids
The thread diam. of the relief where the compensating lens housing goes in is 13/16" across on all the stands, I have seen. The atual lens pak itself, is tightened into the housing with a threaded ring, which is about 1/2" across.
Send me a picture, just to make sure.
I am planning on changing, one of my series 10 stands completely over to bright phase, so I can let the two Dark phase planachros currently in it go.
Those are an AO cat.# 1212 20x and a Reihert cat. # 1213 40x. I also found a source for the 1211 and 1214 planachros to make up a set, if you want.
I will p.m. you.
Send me a picture, just to make sure.
I am planning on changing, one of my series 10 stands completely over to bright phase, so I can let the two Dark phase planachros currently in it go.
Those are an AO cat.# 1212 20x and a Reihert cat. # 1213 40x. I also found a source for the 1211 and 1214 planachros to make up a set, if you want.
I will p.m. you.
Re: Microscopes for kids
I don't know if you are familiar with Pippa's Progress and if it might give you some ideas:PeteM wrote:Two main questions -- one very general and one somewhat specific. The general one -- has anyone run a program like this and have ideas or advice to offer? At this point we're thinking of running weekend groups where adult-kid teams can try various microscopes (or bring their own) and see if this is for them. If it is, we'll try to help them get good affordable scopes or, in some cases, donate a scope. So far, five scopes have gone out -- two to Moms and their kids and three to Dads and their kids.
http://www.microscopy-uk.org.uk/index.h ... .uk/pippa/
Re: Microscopes for kids
Wasn't aware of it -- thanks Gekko.